The training panel was designed for heating and plumbing trainees. A three-way mixing valve in a heating system controls the circulation and feed flow temperature of the water flowing in the heating system. A pump circulates the water in the pipe system. The differential pressure across the pipe system is limited using a relief valve. Bimetallic thermometers indicate the temperatures at all relevant points in the heating circuit. It is possible to assemble a complete heating system by adding other training panels from the Series.